Investments in Unconsolidated Real Estate Joint Ventures Management, Leasing and Marketing Fees (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Management, Leasing and Marketing Fees [Line Items]
Management and Leasing Fees Paid by Unconsolidated Joint Ventures	$ 716	$ 464	$ 1,689	$ 1,399
Marketing Fees Paid by Unconsolidated Joint Venture	37	39	125	119
Total Management, Leasing and Marketing Fees Paid by Unconsolidated Joint Ventures	$ 753	$ 503	$ 1,814	$ 1,518
Deer Park [Member]
Management, Leasing and Marketing Fees [Line Items]
Reduction in Investment Percentage for Profits Earned From Leasing Services	33.30%		33.30%